IRQs: the Hard, the Soft, the Threaded and the Preemptible
summary
Covers Linux interrupt handling internals (hard IRQs, softirqs, tasklets, ksoftirqd) and differences when using the PREEMPT_RT_FULL real-time kernel where hard IRQs become preemptible threads. Explains why softirqs exist, how deferred work is scheduled and managed (including network, timer, and block paths), and shows how to detect IRQ scheduling problems on x86, ARM and ARM64 using tools like bpf, event tracers and mpstat.
AI-written summary · about
related talks
42mUnderstanding Linux Interrupt Subsystem
44mGetting Around to It: Deferred Work in the Linux Kernel
47mWhat Every Driver Developer Should Know about RT
53mPREEMPT_RT - How Not to Break It.
50mInside the RT Patch
34mA Journey into Linux Interrupt Handling Bottom Halves
51mReal Time is Coming to Linux; What Does that Mean to You?
36mJourney of improving RT performance on Single CPU equipped PREEMPT_RT Linux